Canberra is awash with speculation that a Labor leadership spill is imminent, with Prime Minister Kevin Rudd's deputy Julia Gillard being named as likely contender.
It's reported the ALP right in Victoria, New South Wales and South Australia have turned against Mr Rudd, with powerful party factions plotting a leadership challenge.
He's been holding crisis talks with Ms Gillard and other senior ministers this evening.
Gillard's office confirmed the meeting, but stressed that the deputy prime minister was not interested in ousting Rudd as Labor Party leader.
"Nothing has changed," a spokesman for Gillard's office said.
The ABC said senior party figures have been secretly canvassing whether Gillard has enough support to replace Rudd, who is suddenly struggling in the polls as an election looms.
A cabinet source told Sky News that the push was coming from more rightwing elements of the centre-left party.
Senator John Faulkner, who denied any knowledge of the canvassing on ABC Television, earlier joined Treasurer Wayne Swan, frontbencher Anthony Albanese in the prime minister's office.
Trade Minister Simon Crean has backed Mr Rudd, saying he wasn't aware of any leadership challenge.
"I do not support any leadership challenge," Mr Crean said.
"Any loose talk or idle speculation on this matter is counterproductive.
"I urge solidarity behind the leader. I support Kevin as the Leader."
Nine News reported that NSW senator Mark Arbib, Victorian senator David Feeney and parliamentary secretary Bill Shorten told Ms Gillard earlier on Wednesday they'd lost confidence in Mr Rudd and wanted her to run.
She gave no answer.
In another development, the Australian Workers' Union (AWU) is backing Ms Gillard to take over the Labor Party's leadership.
A senior source told AAP on Wednesday night that the AWU had switched their support from Prime Minister Kevin Rudd to Ms Gillard.
Rudd defeated conservative prime minister John Howard in late 2007 and has enjoyed strong popularity until recent months, but his support has slid after a series of missteps and a reinvigorated opposition under leader Tony Abbott.